Session 2: Application of Manures and Fertilisers
Unit 5: Plant Nutrition and Irrigation
Textual Question-Answers
Check Your Progress
Fill in the Blanks
1. Nitrogen in ammonia form takes ————— days afterapplication to be available to plant.
Ans: 3–5
2. A fertiliser is readily soluble and easily available to the plant —————
Ans: nutrient
3. Uniform spreading of manure or fertilisers by hand over theentire surface of field is termed as ——————
Ans: broadcasting
4. Spreading or broadcasting of fertilisers in the standing crop isknown as ——————
Ans: top dressing
5. When fertiliser is placed in bands to the side of seedling, it iscalled ——————
Ans: side placement
Multiple Choice Questions
1. In heavy rainfall areas, the manures may be applied —————
(a) after the monsoon
(b) during monsoon
(c) before monsoon
(d) None of the above
Ans: (c) before monsoon
2. What about plant nutrient is true?
(a) Requirements differ with crop and stages of growth
(b) Efficiency depends on time and methods of application
(c) Crop response to fertiliser application
(d) All of the above
Ans: (d) All of the above
3. Nutrients in manures are ———————
(a) readily available
(b) not available
(c) slowly available
(d) partially available
Ans: (c) slowly available
4. Fertilisers are applied mainly ——————
(a) to supply nutrients to the crops
(b) to correct deficiency
(c) for proper growth and development of crop
(d) All of the above
Ans: (d) All of the above
5. In which form nitrogen is easily available to plants?
(a) Nitrate
(b) Nitrite
(c) Ammonia
(d) None of the above
Ans: (a) Nitrate
6. Manures and fertilisers can be applied —————
(a) during the cultivation of land
(b) after the seed is sown
(c) in standing crop
(d) All of the above
Ans: (d) All of the above
Subjective Questions
1. What are bio-fertilisers? How can they be classified?
Ans: Bio-fertilisers are preparations containing living microorganismswhich help in increasing the availability of nutrients to plants. They areclassified as nitrogen fixing bio-fertilisers, phosphate solubilising biofertilisers and mycorrhizal bio-fertilisers.
2. Write down the precautions that need to be taken while applyingbio-fertilisers.
Ans: Bio-fertilisers should be stored in a cool and dry place, used beforeexpiry date, protected from direct sunlight, mixed with compost or soil before application and should not be mixed with chemical fertilisers or pesticides.
3. What is green manure? What are its advantages anddisadvantages?
Ans: Green manure refers to crops grown and incorporated into the soil at
a tender stage to improve soil fertility. Advantages include improvement ofsoil structure, addition of organic matter and nitrogen. Disadvantages includerequirement of time, water and land which could otherwise be used for maincrops.
4. Compare the advantages of green manure and bio-fertilisers.
Ans: Green manure improves soil physical condition and adds organicmatter, while bio-fertilisers increase nutrient availability through microbial activity. Both help in sustainable soil fertility management and reducedependence on chemical fertilisers.
Match the Columns
A
1. BGA
2. PSBF
3. Azolla
4. Azotobacter
5. Azospirillum
6. Rhizobium
7. VAM
B
(a) Obligate symbiont
(b) Bacteria fix nitrogen in leguminous crops
(c) Bacteria also increase mineral and water uptake
(d) Cyanobacteria
(e) Fern plant, suitable for flooded rice
(f) Convert insoluble soil phosphate into soluble forms
(g) Non-symbiotic bacterium
Ans:
1 – (d) Cyanobacteria
2 – (f) Convert insoluble soil phosphate into soluble forms
3 – (e) Fern plant, suitable for flooded rice
4 – (g) Non-symbiotic bacterium
5 – (a) Obligate symbiont
6 – (b) Bacteria fix nitrogen in leguminous crops
7 – (c) Bacteria also increase mineral and water uptake.
